graphql example

code.py

    @classmethod
    def mutate_and_get_payload(cls, input, context, info):
        user = context.user
        old_password = input.get('old_password')
        new_password = input.get('new_password')

        if user.has_usable_password():
            if not user.check_password(old_password):
                raise ResponseError(
                    "Invalid Password",
                    code='invalid_old_password')
        # ...

req.graphql

mutation {
  changePassword(input: {
    oldPassword: "wrongPassword"
    newPassword: "some-password"
  }) {
    success
  }
}

res.json

{
  "errors": [
    {
      "message": "Invalid Password",
      "code": "invalid-old-password",
      "params": null
    }
  ],
  "data": {
    "changePassword": null
  }
}